In a principal aspect, the present invention relates to the improvement in a three-part drawer slide of a mechanism for controlling the sequence of operation of the separate slide members or channels comprising the slide.
Drawers mounted on slides in filing cabinets often are comprised of multiple, telescoping slide channels. Typically, three or more sliding channels are utilized on each side of a drawer. One of the channels is connected to the wall of the drawer cabinet. A second or intermediate channel slides within the first channel. A third channel is connected to the side of the drawer. Withdrawal of the drawer from the cabinet to open the drawer effects telescoped extension of the second and third channels.
It is often desirable to provide that the channels will move sequentially. That is, typically, the second or intermediate and third channel will move in unison. Thus, if a drawer is partially opened, the second or intermediate channel and third or drawer channel connected to the drawer will first extend or telescope together as a unit fully from the channel connected to the cabinet wall. Thereafter, upon further opening of the drawer, the outer channel or third channel will extend from the second or intermediate channel.
Providing a mechanism to ensure sequential operation of the second and third drawer slide channels is thus a desirable objective.
Briefly, the present invention comprises an improvement in drawer slides having three or more channels. The improvement relates to the mechanism for controlling the sequential operation of the drawer slide channels or elements. In particular, in a construction having a first channel, an intermediate or second channel slidable in the first channel and a third channel slidable in the second or intermediate channel, there is provided a retention mechanism interconnecting the second and third channels. The retention mechanism ensures that the second and third channels move simultaneously as a unit when the assembly of second and third channels is moved from the fully closed toward the open position. Upon reaching the full extension or sliding movement of the second and third channels as a unit in the first or outside channel, a release mechanism disengages the retention mechanism connecting the second and third channels. In a preferred embodiment, the release mechanism comprises a slot or raceway mounted on the first channel that engages a retention pin associated with the second and third channels and releases that retention mechanism. Upon release, the third channel may be telescoped or extended from the second channel thereby permitting the full opening of the drawer.
Thus, it is an object of the invention to provide an improved channel slide construction for drawers having three or more telescoping channels.
It is a further object of the invention to provide a channel slide construction for drawers having three or more channels wherein two of the channels are retained in an interlocked relationship until they telescope in unison in a third channel beyond a fixed distance.
It is a further object of the invention to provide a mechanism for sequential operation of multiple channel members which is economical, rugged, easy to assemble and relatively safe.
These and other objects, advantages and features of the invention will be set forth in the detailed description which follows.